Estimating Biogenic Silica Production of Rhizaria in the Global Ocean

Abstract

Siliceous polycystines and phaeodarians are open‐ocean planktonic protists found throughout the water column and characterized by complex siliceous skeletons that are formed, at least partly, through the uptake of silicic acid. These protists contribute to the marine organic carbon (C) and biogenic silica (bSi) pools, but little is known about their contribution to the silica (Si) biogeochemical cycle. Here we report the first measurements of the Si uptake rate of polycystine and phaeodarian cells from samples collected in the Mediterranean Sea using the 32Si‐based method. The elementary composition (bSi, particulate organic carbon and nitrogen) of these organisms was also measured. Combining our results with published data on the distribution and abundance of Polycystina and Phaeodaria in the global ocean, we conclude that these organisms could contribute from 0.2 to 2.2 mmol Si m−2 of the marine standing stock of bSi and from 2 to 58 Tmol Si yr−1 (1% to 19%) of the global oceanic biogenic silica production. The implications for the global marine Si cycle are discussed.

Carbon and nitrogen content to biovolume relationships for marine protist of the Rhizaria lineage (Radiolaria and Phaeodaria)

“…2C) were collected in the Western Mediterranean basin during the Mediterranean Ocean Observing System on Environment ‐ Grande Echelle (MOOSE‐GE) 2017 cruise. Carbon data on these specimens were previously reported in Llopis Monferrer et al (2020), but have been recalculated to be consistent with the biovolume calculations in this study (e.g., using the same geometric shape formulas for the same groups). Protocystis species P. tridens (PhaeoA, Fig.…”

“…Sampling sites of the MOOSE‐GE cruises, and the sampling location of Villefranche‐sur‐Mer, with an inlay of the Mediterranean Sea ( A ), modified from Llopis Monferrer et al 2020. Estimating biogenic silica production of Rhizaria in the Global Ocean.…”

“…Marine Rhizaria can represent up to 33% of large zooplankton community (> 600 μm) in the upper water column (Biard et al 2016), and are also abundant in deeper layers (Biard and Ohman 2020). Rhizaria are fundamental to many biogeochemical cycles, including silicon (Biard et al 2018;Llopis Monferrer et al 2020), strontium (Bernstein et al 1987), carbon through calcification (Erez 2003), and the sinking of particulate organic matter known as the biological carbon pump process (Lampitt et al 2009;Stukel et al 2018;Gutierrez-Rodriguez et al 2019). The lack of success in culturing Rhizaria and their poor preservation when using conventional sampling methods (Anderson 1983;Suzuki and Not 2015) have limited our basic knowledge about ecology and physiology of these organisms.…”

Massive silicon utilization facilitated by a benthic‐pelagic coupled feedback sustains deep‐sea sponge aggregations

“…Regional patterns of silicic acid availability largely result from the consumption of this nutrient by marine organisms, with diatom utilization in the photic zone among the best known (Nelson et al 1995; Tréguer et al 1995). Other marine organisms also consume silicic acid, such as sponges (Maldonado et al 2012), rhizarians (Llopis Monferrer et al 2020), choanoflagellates (Marron et al 2019), silicoflagellates, testate amoeba, chrysophytes (Simpson and Volcani 1981), and cyanobacteria (Baines et al 2012), but their particular roles in Si cycling remain largely unquantified. Except cyanobacteria, these consumers take up silicic acid and polymerize it as biogenic silica, the fundamental material from which their various types of siliceous skeletons are made.…”

Morpho-molecular diversity and evolutionary analyses suggest hidden life styles in Spumellaria (Radiolaria)

“…509-521 Ma; Suzuki and Oba, 2015;Aitchison et al, 2017;Zhang & Feng, 2019) constituting an important tool for paleoenvironmental reconstructions analysis (e.g., Abelmann and Nimmergut, 2005). In contemporary oceans, molecular-based metabarcoding surveys performed at global scale have shown Radiolaria contribute significantly to plankton communities (de Vargas et al, 2015;Pernice et al, 2016) and silica biogeochemical cycle (Llopis-Monferrer et al, 2020), although very little is known about their ecology and diversity.…”